Design, Application, and Verification of the Novel SEU Tolerant Abacus-Type Layouts

Radiation tolerance improvements for advanced technologies have attracted considerable interests in space application. In this paper, the single event upset (SEU) hardened double interlocked storage cell (DICE) D-type flip-flops (DFFs) with abacus-type time-delay cell are proposed and successfully implemented in our test chips. The layout structures of two kinds of abacus-type time-delay cells are illustrated, and their hardening effectiveness are verified by our simulations and heavy ion irradiations. The systematic heavy ion experimental results show that the applied abacus-type time-delay cells can reduce the SEU cross sections of DICE DFFs significantly, and even the SEU immune is observed for the full “0” data pattern. Besides, an apparent test mode dependency of the abacus-type hardened circuits is also observed. The results indicate that the nanoscale abacus structure may be suitable for space application in harsh radiation environment.